I have a '99 7.3 with 150,000 on it. But it's a single cab and I need a 4 door for the growing family. I've located a 06' but my diesel mechanic has told me to stay away from the 6.0. I pull a 30' 5th wheel a few times a year and an 18' flatbed for work quite often. They act like the 6.0 doesn't hold up to "work". What would you do?